Rolling apparatus

ABSTRACT

A rolling apparatus has a frame and first and second roller mounted in the frame, rotatable about respective first and second axes, forming a nip through which a workpiece passes in a direction of travel, and each having a radially outwardly directed rolling surface that bears radially on the workpiece. The first roller has an axially directed first guide face that bears axially on the workpiece in the nip. A positioning assembly axially positions the first roller relative to the second roller. A shaping die is positioned axially downstream of the nip in the direction and receives the workpiece after it passes through the nip.

FIELD OF THE INVENTION

The present invention relates to a rolling apparatus. More particularlythis invention concerns such an apparatus used to make wire or rod.

BACKGROUND OF THE INVENTION

A rolling apparatus is known having a first and a second rollers mountedin a frame. A workpiece passes through a nip between the rollers. Eachof the rollers has a rolling surface that bears radially on theworkpiece, and at least the first roller has a guide face that bearsaxially on the workpiece. In addition at least the first roller can bemoved axially by a positioning assembly.

U.S. Pat. No. 3,934,446 describes a rolling apparatus for making wire inwhich a blank passes between two driven rollers and is subsequentlyextruded into a wire by a shaping die. The rollers guide the blank bothradially and axially.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide animproved rolling apparatus.

Another object is the provision of such an improved rolling apparatusthat overcomes the above-given disadvantages, in particular that makes along service life of the rollers possible with simple means.

SUMMARY OF THE INVENTION

A rolling apparatus has according to the invention a frame and first andsecond roller mounted in the frame, rotatable about respective first andsecond axes, forming a nip through which a workpiece passes in adirection of travel, and each having a radially outwardly directedrolling surface that bears radially on the workpiece. The first rollerhas an axially directed first guide face that bears axially on theworkpiece in the nip. A positioning assembly axially positions the firstroller relative to the second roller. A shaping die is positionedaxially downstream of the nip in the direction and receives theworkpiece after it passes through the nip.

Thud the rollers press the workpiece through a shaping die immediatelydownstream of the nip of the rollers. In such an arrangement, adjustmentof the guide face in a lateral and/or axial direction is alsoadvantageous because it enables the precise centering of the workpiecerelative to the die. The axial adjustability of the roller thus enablesboth the width and position of the roller nip to be adjusted.

For the same reasons, according to a generally preferred rollingapparatus according to the invention at least one, particularly tworollers are also adjustable radially.

In a simple and especially embodiment of the invention, each of therollers has a guide face that bears on the workpiece axially. Inparticular, the two rollers can be embodied so as to be substantiallymirror images of each other.

It is generally advantageous if each of the rollers can be variablypositioned axially by a respective one of the positioning assemblies,thus allowing for comprehensive adjustment of the roller nip in terms ofwidth and position.

In an embodiment of the invention that can be easily and reliablyimplemented, the positioning assembly comprises a spacer with defineddimensions by means of which an axial position is defined for the rolleron respective drive shaft to which it is splined. The spacer works witha stop for the respective roller on the shaft that is fixed axially onthe respective drive shaft. By providing a commensurately tightlystepped set of spacers, the width and/or position of the roller nip canbe adjusted with minimal effort.

In an alternative embodiment of the invention, the positioning assemblycan also comprise a continuously adjustable stop member that makesarbitrary and/or continuous positioning of the shaft possible. The stopmember can be an adjusting nut, for example.

It is generally advantageous if at least a core of the workpiece is in apartially liquid state when entering the roller nip. This allows for aparticularly low rolling force and, in conjunction with the shaping by adie, also imparts an especially advantageous microstructure to themolded and cooled workpiece. A partially liquid state is understood hereto mean that the material of the workpiece is at a temperature withinthe melting interval of the respective alloy.

A rolling apparatus according to the invention is particularly wellsuited for shaping workpieces that are made of a non-ferrous metal. Morepreferably, the workpiece is made of a light metal and, especiallypreferably, of a magnesium and/or an aluminum alloy. Particularly thecombination of a magnesium alloy and/or an aluminum alloy with extrusionthrough the die in a partially liquid state yields good results. This isespecially true if the roller nip is exactly centered on the die by theadjustment option according to the invention.

Additional advantages and features follow from the embodiment describedbelow as well as from the claims.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, features, and advantages will become morereadily apparent from the following description, reference being made tothe accompanying drawing in which:

FIG. 1 is a partly sectional view through a rolling apparatus accordingto the invention in which the rotation axes of the rollers lie on thesection plane;

FIG. 2 is an overall perspective view of the rolling apparatus of FIG.1; and

FIG. 3 is a partly schematic sectional view through a rolling apparatusaccording to the invention where the roller axes of the rollers areperpendicular to the section plane.

SPECIFIC DESCRIPTION OF THE INVENTION

As seen in FIG. 1, the rolling apparatus comprises a first roller 1 anda second roller 2 that are mounted on respective shafts 3 and 4 in aframe 11. The rollers 1 and 2 are of the same stepped cylindrical shapebut are oriented axially symmetrically oppositely so that their steppedportions 1 a, 1 b, 1 c, 2 a, 2 b, and 2 c of different diameters fittogether. The shafts 3 and 4 are driven to rotate in opposite directionsabout respective shaft axes 3 a and 4 a. Cylindrical outer surfaces 5and 6 of the intermediate-diameter portions 1 a and 2 a directedradially outward confront each other radially. In addition guide faces 7and 8 respectively formed between the portions 1 a and 1 b and theportions 2 a and 2 b axially confront one another. The guide faces 7 and8 are formed on the large-diameter end portions 1 b and 2 b of therollers 1 and 2. Each large-diameter end portion 1 b and 2 b radiallyconfronts the small-diameter portion 2 c and 1 c of the other roller 1or 2.

Thus an axially and radially delimited and/or closed roller nip 9through which a workpiece 10 is conveyed in a travel direction D byrotation of the rollers 1 and 2 is formed by the radially confrontingrolling surfaces 5 and 6 and the axially confronting guide faces 7 and8.

A die 12 through which the partially molten workpiece 10 is pushed orextruded for shaping is positioned directly downstream of the narrowestpoint of the roller nip 9. The die is so close to the rollers 1 and 2and fits with them such that the workpiece 10 cannot escape laterally.Downstream of the die 12 is a tubular outlet guide 13 for guiding andcooling the extruded workpiece 10.

The workpiece 10 preferably enters the roller nip 9 in a partiallyliquid state. This applies at least to a core of the workpiece 10, withit being possible for an outer-surface part to already be solidifieddepending on the circumstances and process parameters. The partiallyliquid state is preferably achieved after melting and casting of thealuminum/magnesium alloy material to be extruded in the same heat.

Since the axially confronting guide faces 7 and 8 are in frictionalcontact with the workpiece 10 there is wear not only on the rollingsurfaces 5 and 6 but also on these guide faces 7 and 8.

According to the invention, in order to restore the lateral delimitationof the roller nip 9 after wear, the rollers 1 and 2 can be adjustablypositioned axially by respective positioning assemblies 14 on the shafts3 and 4. The positioning assemblies 14 comprises respective spacers 15and 16 against which the respective rollers 1 and 2 abut after beingpushed axially onto the respective shafts 3 or 4. The selectablydimensioned spacers 15 and 16, in turn, abut against respective stops 17and 18 that are fixed on the shafts 3 and 4.

The spacers 15 and 16 have defined axial dimensions, so that the axialpositions of the rollers 1 and 2 on their shafts 3 and 4 are definedthrough appropriate selection of the spacer size. The rollers 1 and 2positioned in this way are each held tightly by the respective spacers15 and 16 against respective abutments 19 and 20. In this embodiment,the positioning assemblies 14 thus comprise the abutments 17, 18, 19 and20 and the spacers 15 and 16. The rollers 1 and 2 are axially shiftableon the shafts 3 and 4 that are axially fixed and on which the abutments17-20 are also axially fixed.

The system for positioning the shafts 3 and 4 and rollers 1 and 2radially is not shown. This is achieved in a known manner via bearingsholding the shafts 3 and 4. The overall height or radial dimension ofthe roller nip 9 can thus also be adjusted. In particular, this ensuresthat the workpiece 10 passes through the rollers 1 and 2 so as to becentered precisely in front of the die.

I claim:
 1. A rolling apparatus comprising: a frame; first and secondroller mounted in the frame, rotatable about respective first and secondaxes, forming a nip through which a workpiece passes in a direction oftravel, and each having a radially outwardly directed rolling surfacethat bears radially on the workpiece, the first roller having an axiallydirected first guide face that bears axially on the workpiece; a firstpositioning assembly for axially positioning the first roller relativeto the second roller; and a shaping die positioned axially downstream ofthe nip in the direction and receiving the workpiece after passingthrough the nip.
 2. The rolling apparatus defined in claim 1, whereinthe second roller has an axially directed second guide face engaging theworkpiece and axially confronting the first guide face.
 3. The rollingapparatus defined in claim 1, further comprising: a second positioningassembly for axially positioning the first roller relative to the firstroller.
 4. The rolling apparatus defined in claim 1, further comprising:respective first and second shafts on which the rollers are carried, thefirst positioning assembly including a removable first spacer bracedaxially between the first roller and the first shaft and of apredetermined axial dimension.
 5. The rolling apparatus defined in claim1, wherein the positioning assembly includes a nut threaded on the firstshaft and rotatable to steplessly axially position the first roller. 6.The rolling apparatus defined in claim 1, wherein a core of theworkpiece is in a partially liquid state when entering the roller nip.7. The rolling apparatus defined in claim 1, wherein the workpiece ismade of a magnesium and/or an aluminum alloy.